Adding setup command for rmt-cli to update database and scc configs [Issue#987]

[likhitha77]

Description

Adding the "setup" command for the rmt-cli : rmt-cli setup

Currently users must manually create or alter the /etc/rmt.conf file to update certain configs like database values and scc credentials. This rmt-cli setup command aims to automate this process.

It performs the following actions:

• Copies ./config/rmt.yml to etc/rmt.conf file, if etc/rmt.conf is not present
• Interactively prompts users to provide the database and scc cofigurations. If any configs have been defined previously, it displays the existing value to the user so they can review it before updating it. They can simply hit enter to retain the previous value as is. ( Example => username (Press enter for John ) : )
• Provides the option to restart the RMT server automatically with the updated configurations. Users can chose to manually restart RMT as well.

Fixes issue : #987

Change Type

Please select the correct option.

• Bug Fix (a non-breaking change which fixes an issue)
• New Feature (a non-breaking change which adds new functionality)
• Documentation Update (a change which only updates documentation)

Checklist

Please check off each item if the requirement is met.

• I have verified that my code follows RMT's coding standards with rubocop.
• I have reviewed my own code and believe that it's ready for an external review.
• I have provided comments for any hard-to-understand code.
• I have documented the MANUAL.md file with any changes to the user experience.
• RMT's test coverage remains at 100%.
• If my changes are non-trivial, I have added a changelog entry to notify users at package/obs/rmt-server.changes.

Other Notes

Run bin/rmt-cli setup command to start the setup.

Note:
If a previously configured value for any config exists, it will be displayed in the prompt to preview. ( Example => username (Press enter for John ) : ) . If you wish to alter it, enter a new value. If you do not wish to alter it, just hit enter.